Turning a versatile material into a smart thermometer

In Latvia’s current heat wave, you don’t need a PhD to tell you to go to the beach. But for sensitive goods, knowing they are kept at a safe temperature is trickier than feeling sweat on your brow.

Inga Pudža, a researcher assistant at the University of Latvia’s Institute of Solid State Physics EXAFS Spectroscopy Laboratory, is working on just such a solution. She is studying molybdate, a copper compound which changes colour at extreme temperatures and could potentially tell shippers of vaccines, medicines and food if their cargoes might have been a little too warm or cool.

“It’s like an indicator that the product has been outside its comfort zone and may be spoiled,” says Inga.

Copper molybdate is a cheap and common material, which in addition to being thermo-chromatic is also responsive to pH levels and pressure and has antibacterial properties. As part of her doctoral thesis, Inga bombards samples of molybdate powder with X-rays, then analyses the behaviour of the atoms. She then travels to France, Germany, Italy or Sweden to conduct week-long experiments in large accelerators (synchrotrons), returning to Riga with plenty of datafor analysisand modelling on a super computer.All of this is aimed at understanding why the material changes its colour and how to adapt it to get the desired characteristics.

At present, this is fundamental research without a specific commercial client. But Inga believes it could be used as an additional verifying agent, or incorporated into sensors as a new technology. It would be cheaper than electronic devices, which can also malfunction due to dead batteries or other technical problems, and more durable than organic materials, which are not stable atvery high temperatures.

Source: laboflatvia.com